This invention relates to the generation of X-rays and, more particularly, to an X-ray source characterized by high power.
X-ray generators are utilized in a variety of applications of practical importance. One significant area in which such sources are employed is the field of X-ray lithography. An advantageous X-ray lithographic system utilized to make structures such as large-scale-integrated (LSI) semiconductor devices is described in IEEE Transactions on Electron Devices, Vol. ED-22, No. 7, July 1975, pages 429-433. In an attempt to increase the throughput of such an X-ray lithographic system, considerable effort has been directed at trying to develop more sensitive resist materials for utilization therein and, moreover, at trying to increase the power output of the X-ray generator included in such a system.
High-power X-ray sources including rotating water-cooled anodes are available for use in lithographic systems. However, maintenance and reliability considerations make this type of source unattractive for some lithographic applications. Accordingly, efforts by workers in the lithographic field have been directed at trying to devise a high-power X-ray source having a stationary anode and characterized by high stability, long lifetime and low maintenance. It was recognized that such a source, if available, could be, for example, the basis for a rugged production-type X-ray lithographic system exhibiting advantageous throughput properties.